PSG were complacent and sloppy at Lyon and rightfully lost. But it could be a blessing in disguise.

The dream is over. PSG's fantastic run of 27 unbeaten league games this season ended on Sunday evening in Lyon with a 2-1 defeat. Their dream of completing a whole campaign without losing a game -- something that has never been done in the history of French football and very rarely in the history of the five big European leagues, either -- is now gone.

This team is probably the best to have ever graced the top flight in France, they already have made history on many levels and more records are still attainable this season. But the biggest one of all, the invincible one, would have been the most telling and the most impressive -- far more so than setting a new points record or scoring the most goals.

All in all, over two seasons, PSG made it 36 matches in a row in the league without losing once. It's a record of its own but they fell 11 games shy of making it a full unbeaten season, and five short of equalling the single-season record set by Nantes in 1995.

Losing a game was going to happen eventually and Sunday's fixture, away at Lyon, always looked like the most perilous trap left for PSG. However, the loss came when Laurent Blanc's team looked their strongest. They dominated Chelsea 10 days ago in the Champions League and endured a tough game away at Marseille, not looking like they would lose in Lyon. But virtually from the kickoff, you could feel Ibra & Co. would have a rocky night. OL were in their faces, winning duels and second balls with more desire, more motivation and more hunger.

Bruno Genesio and his players deserve a lot of credit for being the first ones to make PSG fall. They never let them play and produced a near-perfect performance of their own. Watching their celebrations at the final whistle showed what the victory meant to them, both in terms of the overall season and their own position in the table as they race for second place.

So what happened to the Parisians? They already had beaten this Lyon side four times in the season prior to Sunday. They weren't always straightforward, but they still managed four wins in four! The absence of Marco Verratti and Angel Di Maria, not 100 percent fit, made a big difference. PSG are not the same without them.

Laurent Blanc was angry following Sunday's defeat even though his XI selections were made with Chelsea in mind.

If, as was the case last season, Lyon had been top of the table and PSG needed a win to stay in touch with the title race, Blanc surely would have started his two stars. Yet the French champions were 23 points clear of second-place Monaco before Sunday's game; the priority is Chelsea next week and it showed, with several of Blanc's players seemingly already on their way to Stamford Bridge.

David Luiz's attitude, for example, was far from his expected best. Same with Ibrahimovic. It's usually OK for PSG to not be fully focused on Ligue 1 duties because they've been so superior that poor games still ended in victory. But not on Sunday. To beat this Lyon team and the way they played, PSG needed everybody focused and ready to put in a strong display. It was not the case; Blanc blasted his players for that after the game.

What was interesting on Sunday is that we saw the Lyon team of last season, the one that came so agonisingly close to winning the league. Their movement was great, the intensity in their game was impressive and they were such a threat going forward that they could have easily scored more than twice. We also saw too much of last season's PSG and their flaws too; a lot of nonchalance, minimum effort with the belief that it would be enough to win or at least not to lose. The passing was lazy, the rhythm was too slow and they kept making the wrong choices on the ball. PSG and Lyon have rarely been like they were on Sunday, which explains why they are where they are currently in the table.

Finding the positive for PSG, this defeat may have arrived at the right time, 10 days before the biggest game of the season to date, away at Chelsea, in a wonderfully anticipated second leg. It's a timely reminder that despite all the talent in the world, you cannot afford to take games for granted, especially while trying to make a deep run in the Champions League.

A word of warning to Chelsea though: Don't expect to see Sunday's version of PSG next week. Be assured they will be up for it and still hurting from watching their dream of becoming French football's first invincibles go up in smoke.

Julien Laurens is a London-based French journalist who writes for ESPN FC and Le Parisien. Follow him on Twitter: @LaurensJulien.